Techniques for sidelink sensing and positioning
This disclosure provides systems, methods and apparatus, for measurement and reporting procedures associated with a sidelink positioning reference signal (SL-PRS). In one aspect, a first user equipment (UE), which may function as a sidelink anchor node, may transmit an SL-PRS to a second UE in accordance with a slot format or structure that is dedicated for SL-PRS transmissions. The first UE may select resources for the transmission of the SL-PRS via sensing and exclusion or using a set of resources that are dedicated for SL-PRS transmissions. The second UE may receive the SL-PRS and use the SL-PRS to acquire positioning information, in accordance with an observed time difference of arrival (OTDOA)-based positioning method, or may transmit a second SL-PRS to the first UE to facilitate acquisition of positioning information at the first UE, in accordance with a round-trip-time (RTT)-based positioning method.
1. A wireless device, comprising:
a processing system that includes one or more processors and one or more memories coupled with the one or more processors, the processing system configured to cause the wireless device to:
obtain control information indicating resources allocated for selection by wireless devices for performing sidelink communications; and
output a positioning reference signal (PRS) in accordance with a transmission time interval (TTI) associated with the resources allocated for selection by wireless devices for performing sidelink communications, the TTI being associated with a slot format including a PRS portion and one or more gap durations adjacent to the PRS portion.
2. The wireless device of claim 1 , wherein the processing system is further configured to cause the wireless device to:
obtain, from a second wireless device, a PRS request, wherein outputting the PRS is associated with obtaining the PRS request.
3. The wireless device of claim 1 , wherein the processing system is further configured to cause the wireless device to:
obtain, from a second wireless device, a second PRS in response to outputting the PRS.
4. The wireless device of claim 3 , wherein the processing system is further configured to cause the wireless device to:
output, via sidelink control information (SCI) associated with the TTI, an indication of a resource to be used for outputting the second PRS; and
obtain the second PRS using the resource.
5. The wireless device of claim 1 , wherein the processing system is further configured to cause the wireless device to:
obtain, from a second wireless device, a second PRS preceding the outputting of the PRS, wherein outputting the PRS is associated with obtaining the second PRS.
6. The wireless device of claim 1 , wherein the slot format is dedicated for sidelink PRS transmissions.
7. The wireless device of claim 6 , wherein the slot format comprises a physical sidelink control channel (PSCCH) portion, a second stage sidelink control information (SCI) portion, one or more demodulation reference signal (DMRS) portions, a PRS burst portion including the PRS portion, and the one or more gap durations adjacent to the PRS burst portion.
8. The wireless device of claim 7 , wherein the processing system is further configured to cause the wireless device to:
output control signaling indicating one or both of the slot format or a PRS pattern for the outputting of the PRS; and
output the PRS during the PRS burst portion and using one or both of the slot format or the PRS pattern.
9. The wireless device of claim 1 , wherein the processing system is further configured to cause the wireless device to:
output, via sidelink control information (SCI) associated with the PRS, an indication of a position of the wireless device, a transmission timing of a transmission of the PRS, an indication of a PRS pattern associated with the PRS, an indication of a PRS pattern for a responsive PRS, an indication of a transmission power for the PRS, or any combination thereof.
10. The wireless device of claim 1 , wherein the processing system is further configured to cause the wireless device to:
output an indication of sidelink control information (SCI) reserving a set of periodic resources of the resources allocated to sidelink communications; and
output the PRS using the set of periodic resources.
11. The wireless device of claim 1 , wherein the processing system is further configured to cause the wireless device to:
output, in accordance with the TTI, a second PRS using a different sub-channel or using a different resource pool than the PRS, the outputting of the second PRS having phase continuity with the outputting of the PRS.
12. The wireless device of claim 1 , wherein the PRS is output using resources, of the resources allocated for selection by wireless devices for performing sidelink communications, that are dedicated for PRS transmissions.
13. A first wireless device, comprising:
a processing system that includes one or more processors and one or more memories coupled with the one or more processors, the processing system configured to cause the first wireless device to:
obtain control information indicating resources allocated for selection by wireless devices for performing sidelink communications; and
obtain, from a second wireless device, a positioning reference signal (PRS) in accordance with a transmission time interval (TTI) associated with the resources allocated for selection by wireless devices for performing sidelink communications, the TTI being associated with a slot format including a PRS portion and one or more gap durations adjacent to the PRS portion.
14. The first wireless device of claim 13 , wherein the processing system is further configured to cause the first wireless device to:
output a PRS request, wherein obtaining the PRS is associated with outputting the PRS request.
15. The first wireless device of claim 14 , wherein the PRS request comprises an indication of sidelink control information (SCI), an indication of a medium access control (MAC) control element (CE), or radio resource control (RRC) signaling.
16. The first wireless device of claim 14 , wherein the processing system is further configured to cause the first wireless device to:
obtain, via sidelink control information (SCI) associated with the PRS, an indication of a position of the second wireless device and an indication of a transmission timing of the PRS from the second wireless device, wherein a position of the first wireless device is determined using the position of the second wireless device and the transmission timing of the PRS from the second wireless device.
17. The first wireless device of claim 13 , wherein the apparatus processing system is further configured to cause the first wireless device to:
output a second PRS, wherein obtaining the PRS is associated with outputting the second PRS.
18. The first wireless device of claim 13 , wherein the processing system is further configured to cause the first wireless device to:
obtain, via sidelink control information (SCI) associated with the PRS, an indication of the slot format, wherein the slot format is dedicated for sidelink PRS transmissions; and
obtain the PRS in accordance with the slot format.
19. The first wireless device of claim 13 , wherein the processing system is further configured to cause the first wireless device to:
obtain, via sidelink control information (SCI) associated with the PRS, an indication of a position of the second wireless device, a transmission timing of the PRS, an indication of a PRS pattern associated with the PRS, an indication of a transmission power associated with the PRS, or a combination thereof.
20. The first wireless device of claim 13 , wherein the processing system is further configured to cause the first wireless device to:
obtain an indication of sidelink control information (SCI) reserving a set of periodic resources of the resources allocated for selection by wireless devices for performing sidelink communications; and
obtain the PRS using the set of periodic resources.
21. A method for wireless communication at a wireless device, comprising:
receiving control information indicating resources allocated for selection by wireless devices for performing sidelink communications; and
transmitting a positioning reference signal (PRS) in accordance with a transmission time interval (TTI) associated with the resources allocated for selection by wireless devices for performing sidelink communications, the TTI being associated with a slot format including a PRS portion and one or more gap durations adjacent to the PRS portion.
22. The method of claim 21 , further comprising:
receiving, from a second wireless device, a PRS request, wherein transmitting the PRS is associated with receiving the PRS request.
23. The method of claim 21 , further comprising:
receiving, from a second wireless device, a second PRS preceding the transmitting of the PRS, wherein transmitting the PRS is associated with receiving the second PRS.
24. The method of claim 21 , wherein the slot format is dedicated for sidelink PRS transmissions.
25. The method of claim 21 , further comprising:
transmitting, via sidelink control information (SCI) associated with the PRS, an indication of a position of the wireless device, a transmission timing of a transmission of the PRS, an indication of a PRS pattern associated with the PRS, an indication of a PRS pattern for a responsive PRS, an indication of a transmission power for the PRS, or any combination thereof.
26. A method for wireless communication at a first wireless device, comprising:
receiving control information indicating resources allocated for selection by wireless devices for performing sidelink communications; and
receiving, from a second wireless device, a positioning reference signal (PRS) in accordance with a transmission time interval (TTI) associated with the resources allocated for selection by wireless devices for performing sidelink communications, the TTI being associated with a slot format including a PRS portion and one or more gap durations adjacent to the PRS portion.
27. The method of claim 26 , further comprising:
transmitting a PRS request, wherein receiving the PRS is associated with transmitting the PRS request.
28. The method of claim 26 , further comprising:
transmitting a second PRS, wherein receiving the PRS is associated with transmitting the second PRS.
29. The method of claim 26 , further comprising:
receiving, via sidelink control information (SCI) associated with the PRS, an indication of the slot format, wherein the slot format is dedicated for sidelink PRS transmissions; and
receiving the PRS in accordance with the indicated slot format.
30. The method of claim 26 , further comprising:
receiving, via sidelink control information (SCI) associated with the PRS, an indication of a position of the second wireless device, a transmission timing of the PRS, an indication of a PRS pattern associated with the PRS, an indication of a transmission power associated with the PRS, or a combination thereof.